There are living citizens of Britain who were born before mass representative democracy. Not all women had the vote until 1929; not all men until 1918, and it took the atrocity exhibition of the Great War to shame the state into their enfranchisement.

This, I stress, is Britain, centuries-steeped in political enlightenment. In other countries, representative democracy has even wispier roots. The norm we have grown up with, of the greater share of the population being free to choose its rulers, has been around for the historical equivalent of the time it takes to cough. During its most severe test, the second world war, it was suspended. During another great trial, the inter-war depression, it surrendered to strongmen in cultures as sophisticated as Germany and Italy.

It is innately difficult to imagine the end of the one political system we have ever known. When we try — and many far-from-hysterical commentators have been moved to since the rise of Donald Trump as US president, the moderate conservative David Frum among them — the dread is always an authoritarian dictatorship. In a typical dystopia, Mr Trump is in the third term of his two-term presidency, Britain is ruled by (depending on your fevered nightmare of choice) Tories hostile to foreigners or socialists hostile to property rights, and France finally consummates its flirtation with the National Front.